This invention relates to a drive unit for folding or unfolding rows of seats or benches arranged in a telescopic seating system.
Various devices are known in the art for extending or retracting bleachers, such as may be found in an indoor athletic facility. U.S. Pat. No. 4,285,172 to Quigley teaches a powered drive apparatus which folds and unfolds rows of bleachers and which is adapted to fit almost entirely beneath a deck of the lowermost row. A roller, defined therein as having an axial dimension larger than its radius, is provided at central portions of a front and a rear of a frame, each roller extending on respective axles transverse to the direction in which bleachers are moved by the apparatus. U.S. Pat. No. 3,282,363 to Curra discloses a tractor means for extending and retracting bleacher stand sections. The tractor means includes a frame into which a drive for tread members is centrally mounted. Wheels, provided at each corner of the tractor means, are normally spaced from the floor during operation of the tractor means. U.S. Pat. No. 3,872,943 to Olson, although not disclosing an apparatus used for moving bleacher rows, teaches a drive unit for transporting pipe sections wherein wheels at each corner of a supported frame contact the ground.
While the foregoing devices may be deemed suitable for their respective intended purposes, room for improvement still exists in the art.